Brad Marshall wrote:If history has taught us anything there doesn't seem to be a limit for human endurance. Every year people are pushing the boundaries further and further. If Everest were 35,000 feet someone would eventually get to the top, probably with improved oxygen gear. Then someone would come along and do it without oxygen and us mere mortals would once again be amazed.

The only limits are those we place upon ourselves. We once thought the world was flat, now look at us. We dove to the deepest point in the ocean, climbed the highest mountain, broke the 4-minute mile, run ultra-distance marathons in desert heat and flown to the moon. Wow, what's next!

The only limits are those we place upon ourselves. We once thought the world was flat, now look at us. We dove to the deepest point in the ocean, climbed the highest mountain, broke the 4-minute mile, run ultra-distance marathons in desert heat and flown to the moon. Wow, what's next!

What's next Brad? A human on Mars. But that won't happen in my lifetime.

The only limits are those we place upon ourselves. We once thought the world was flat, now look at us. We dove to the deepest point in the ocean, climbed the highest mountain, broke the 4-minute mile, run ultra-distance marathons in desert heat and flown to the moon. Wow, what's next!

The only limits are those we place upon ourselves. We once thought the world was flat, now look at us. We dove to the deepest point in the ocean, climbed the highest mountain, broke the 4-minute mile, run ultra-distance marathons in desert heat and flown to the moon. Wow, what's next!

What's next Brad? A human on Mars. But that won't happen in my lifetime.

Do you have a self-imposed limit on your lifetime Bryan or are you going to push the limits? If not for us then for all those young serving girls!

No! I'll keep going as long as there is a chance of "something happening" with a dirndl wearing Bavarian Serving Wench.

But I just have this feeling that an attempt to send someone to Mars is maybe 50 years or more away.

By which time Everest will have grown a bit more, and humankind would have developed so much more that there will be a paved trail to the summit for Sunday afternoon walkers. Well, maybe not quite. But heading in that direction.

Do you have a self-imposed limit on your lifetime Bryan or are you going to push the limits? If not for us then for all those young serving girls!

No! I'll keep going as long as there is a chance of "something happening" with a dirndl wearing Bavarian Serving Wench.

But I just have this feeling that an attempt to send someone to Mars is maybe 50 years or more away.

By which time Everest will have grown a bit more, and humankind would have developed so much more that there will be a paved trail to the summit for Sunday afternoon walkers. Well, maybe not quite. But heading in that direction.

Do you have a self-imposed limit on your lifetime Bryan or are you going to push the limits? If not for us then for all those young serving girls!

No! I'll keep going as long as there is a chance of "something happening" with a dirndl wearing Bavarian Serving Wench.

But I just have this feeling that an attempt to send someone to Mars is maybe 50 years or more away.

By which time Everest will have grown a bit more, and humankind would have developed so much more that there will be a paved trail to the summit for Sunday afternoon walkers. Well, maybe not quite. But heading in that direction.

Brad Marshall wrote:If history has taught us anything there doesn't seem to be a limit for human endurance. Every year people are pushing the boundaries further and further. If Everest were 35,000 feet someone would eventually get to the top, probably with improved oxygen gear. Then someone would come along and do it without oxygen and us mere mortals would once again be amazed.

I'm inclined to agree with that.

But there's an upper limit somewhere. Olympus Mons, for one.

I was in the Canadian Air Force in the 1960's, working on the CF104 supersonic jet fighter. That jet was designed to reach 100,000 feet. So the pilot's ejection seat was designed so he would survive the fall, if he ejected from that altitude.

First of all, he'd be breathing an oxygen-air mix already.

For the descent, his seat carried a bottle of O2 that would let him breathe at least down to 20,000 feet -- I think 10 minutes. While falling, his body is idle, so his O2 requirement should be low. Note that his parachute is NOT deployed for the fall. He has only enough oxygen to fall to 20,000 directly (do not stop at go).

The ejection seat assumes that the pilot is unconscious. There had to be a desperate reason why he bailed, and also during the fall, if anything went wrong, he'd no longer have a guarantee of oxygen delivery.

At around 20,000 feet the seat automatically cuts loose, although his survival pack is still tethered below him.

Finally at 10,000 feet (I think) the parachute automatically deploys, and he floats gently to the ground.

Limits to altitude?

I've heard of 16,000 feet marks the "death zone" because the body can no longer rebuild wear-and-tear, and slowly but inexorably begins to die.

The climbers who reach to summit of Everest without oxygen are extra-ordinary folks, and from their stories, you know they've reached the limit.

dan2see wrote:I was in the Canadian Air Force in the 1960's, working on the CF104 supersonic jet fighter. That jet was designed to reach 100,000 feet. So the pilot's ejection seat was designed so he would survive the fall, if he ejected from that altitude.

First of all, he'd be breathing an oxygen-air mix already.

For the descent, his seat carried a bottle of O2 that would let him breathe at least down to 20,000 feet -- I think 10 minutes. While falling, his body is idle, so his O2 requirement should be low. Note that his parachute is NOT deployed for the fall. He has only enough oxygen to fall to 20,000 directly (do not stop at go).

The ejection seat assumes that the pilot is unconscious. There had to be a desperate reason why he bailed, and also during the fall, if anything went wrong, he'd no longer have a guarantee of oxygen delivery.

At around 20,000 feet the seat automatically cuts loose, although his survival pack is still tethered below him.

Finally at 10,000 feet (I think) the parachute automatically deploys, and he floats gently to the ground.

Imagine, the pilot successfully ejects at 100,000 feet; the oxygen system works perfectly for the unconscious pilot, and it keeps him alive to 20,000 feet; the seat automatically separates at 20,000 feet, just as designed. Everything works perfectly, and the unconscious pilot's parachute will automatically deploy at 10,000 feet. . . .

Day Hiker wrote:[snip]. . . But he was flying over 11,000-foot terrain.

Sure, shit happens! You know from your own experience that your "gear" helps you survive. But you gotta admit that those old jet fighter's ejector seats delivered a much higher survival rate than today's avalanche beacons.

Don't forget, this thread's OP asked how high a climber could get above Everest. Some posts guessed on endurance, or training.

But my account was meant to illustrate how hard it must be to survive extremely high altitude.

The max theoretical altitude that can be reached without oxygen is 9250 m at Everestlatitude where the partial pressure is 240 mm Hg. Few humans can breath at this very low pressure.....( at Denali Latitude this cannot be reached because the lower mass of total atmosphera on it).

dan2see wrote:I was in the Canadian Air Force in the 1960's, working on the CF104 supersonic jet fighter. That jet was designed to reach 100,000 feet.

Must have been a very interesting career. Canadian aviation design was at its peak in the 50s designing the CF-105. What a sad story for our country. I recently purchased a diecast model of the Arrow, just released from the Canadian Air and Space Museum in Toronto, that sits on my office desk to remind me of what we are capable of doing.